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This article mainly explains the difference and use of iTunes + and + + I in Java. The explanation in this article is simple and clear and easy to learn and understand. Please follow the editor's train of thought to study and learn the difference and use of iTunes + and + + I in Java.

The explanations of I + + and + + I in the book are as follows:

Int I = 3 ·a = 0; I + +: first assign a value and then operate; for example: a = I + +; assign a = I first, then operate I = I + 1; so the output result is a = = 3 + I: first operate and then assign; for example: a = I + +; first operate I = I + 1, then assign a = I; so the output result is a = 4

Do you understand? I think most people will be as confused as I am, obviously + 1, how come the output above is 3 and below is 4? Haha ~ don't worry, next I will share my understanding of them, I hope it will be helpful to you.

Know "+ +" and "-"

"+" and "-" are called self-increment operators and self-subtraction operators, respectively, and they are operators that add 1 and subtract 1 to a variable.

Recognize iPlus + and iMushue + as addition and subtraction, called post-increment operator and post-subtraction operator, respectively.

Let's first introduce the calculation method of ibasket +, which is divided into the following five steps

First batch a temporary storage area to copy the value of I to the storage area I itself + 1 temporary storage value waiting to be called (participate in operation, output, assignment) if I is called, the output value is I, otherwise output iTunes +

The illustration is as follows:

Next, I'll give you an example.

Public class test {public static void main (String [] args) {int I = 3; / * create a variable I, in which the initial value of I is 3. Open up a temporary storage area and copy the value of I to the storage area. In this case, the value of I in the storage area is 3 * / I + +; / / I itself plus 1, and the value of I is 4 System.out.print (I). / / print out I, because I is not called, so the value of I itself is 4 System.out.print (iTunes +); / * the value of I in the previous line of code has become 4, then open up a temporary storage area and copy the value of I to the storage area. At this time, the value of I in the storage area is 4, and the value of I itself + 1 becomes 5. Int + is called by the output, so the value of the output store is 4 * / output j = iDepot; System.out.print (j); / * the value of I in the previous line of code has changed to 5. Then open up a temporary storage area and copy the value of I to the storage area. At this time, the value of I in the storage area is 5, and the value of I itself + 1 becomes 6. IShop + is called by assignment, so the value of output store is 5 * / System.out.print (I); / / is not called, so the print value is the value of I itself 6; System.out.print (I); / * the value of I in the previous line of code has become 6, and then open up a temporary storage area to copy the value of I to the storage area, where the value of I in the storage area is 6, the value of I, + 1, becomes 7. IShop + is called by assignment, so the value of I in the output store is 6 * / I = iDiagram; System.out.print (I); / * the value of I in the previous line of code is 6, and then a temporary storage area is opened and the value of I is copied to the storage area. In this case, the value of I in the storage area is 6 * /}, where the value of I itself + 1 changes to 7, and ibasket + is called, so the value of the output store is 6 * /}

In the same way, the calculation method of I-is as follows

First batch a temporary storage area to copy the value of I to the storage area I itself-1 temporary storage value waiting to be called (participating in operation, output, assignment) if I is called, the output value is I, otherwise the output I--

Give examples to illustrate

Public class test01 {public static void main (String [] args) {int I = 5; / * create a variable I, in which the initial value of I is 5. First, open up a temporary storage area and copy the value of I to the storage area. In this case, the value of I in the storage area is 5 * / I muster hand I itself minus 1, and the value of I is 4 System.out.println (I). / / print out I, because I is not called, so the value of I itself is 4 System.out.print (iMel -); / * the value of I in the previous line of code has become 4, and then open up a temporary storage area to copy the value of I to the storage area. At this time, the value of I in the storage area is 4, and the value of I itself-1 becomes 3. I int-is called by the output, so the value of the output store is 4 * / int j = I Murray; System.out.print (j); / 3 / * the value of I in the previous line of code has changed to 4, and then open up a temporary storage area to copy the value of I to the storage area. At this time, the value of I in the storage area is 4, and the value of-1 becomes 3. IMube-the value of the output store is 3 * / System.out.print (I); / / is not called, so the print value is the value of I itself 3 I = iMurray; System.out.print (I); / 2 / * the value of I in the previous line of code has become 3, and then open up a temporary storage area to copy the value of I to the storage area, where the value of I in the storage area is 3, the value of I itself-1 becomes 2 IMurt-is called by assignment, so the value of the output store 2 * /}}

Know + + I and-- I

+ + I is pronounced "plus imai" and "subtractive I", which is called pre-increment operator and pre-self-subtraction operator respectively. The operation idea of + + I is relatively simple compared with iPremium +, and only a simple + 1 operation can be carried out.

Examples are as follows:

Public class test {public static void main (String [] args) {I = 1; j = iSum + + + iLiv + + iLiv + + I + iLiv: assignment call, so the print value is 1, the value put in the temporary storage area is 2 + + iVOR value + 1, so the value is 3 + + iString value + 1, so the value is 4 System.out.print (j): the value of output temporary storage area is 4, and the value is 5 * / System.out.print (j). / / so the output result is 12 System.out.print (I); / / does not participate in the call, so the output value of I itself is 5 System.out.print (+ + I); / / the output value is 6

By the same token,-- I, but only on its own basis-1 can.

Examples are as follows:

Public class test01 {public static void main (String [] args) {int I = 5;-- I; System.out.println (I); / / I itself minus 1, the value is 4 System.out.print (--I); / / I itself minus 1, the value is 3}}

Using self-increment and self-subtraction operators can make expressions shorter, but they can also make them more complex and difficult to read. For example, in the above code, j = ilevels + + + icycles + + I + icycles; just to test whether we have a better grasp of icycles + and + + I, but should be avoided in the actual programming process.

My summary is as follows:

If you participate in the call, the output value is not + 1, otherwise + 1 + + I,-- I: regardless of whether you participate in the call or not, the output value is + 1. I hope you can use these two sentences reasonably on the basis of reading my above description.

PS: is it easy to use my method to do the problem at the beginning of the article?

Int I = 3, a = 0

I + +: for example: a = I + +; because the assignment is called, the output value is the value of I copied by the temporary storage first, that is, a = = 3

+ I: for example: a = I + +; the output result is directly + 1, that is, the result is a = = 4

Thank you for your reading, the above is the content of "the difference and use of iTunes + and + + I in Java". After the study of this article, I believe you have a deeper understanding of the difference and use of iTunes + and + + I in Java, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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